Наредни састанак Семинара биће одржан у петак, 8. новембра 2024. године, у сали 301ф Математичког института САНУ са почетком у 14.15 часова.
Предавач: Иван Дамњановић, Електронски факултет, Ниш
Наслов: ON THE SPECTRAL RADIUS OF THRESHOLD GRAPHS
Апстракт: The spectral radius of a graph is the spectral radius of its adjacency matrix. A threshold graph is a simple graph whose vertices can be ordered as v_1, v_2,…, v_n, so that for each 2 ≤ i ≤ n, vertex v_i is either adjacent or nonadjacent to all of v_1, v_2,…, v_{i-1}. Brualdi and Hoffman initially posed and then partially solved the extremal problem of finding the simple graph with a given number of vertices and edges that has the maximum spectral radius. This problem was subsequently completely resolved by Rowlinson. Here, we deal with the similar problem of maximizing the spectral radius over the set of connected simple graphs with a given number of vertices and edges. As shown by Brualdi and Solheid, each such extremal graph is necessarily a threshold graph. We investigate the spectral radii of threshold graphs by relying on computations involving la zy walks. Furthermore, we obtain certain lower and upper bounds on the spectral radius of a given threshold graph. (This is a joint work with Peter Csikvari, Dragan Stevanović and Stephan Wagner).
Напомена: Предавање се може пратити на даљину преко линка Одељења за математику: https://miteam.mi.sanu.ac.rs/asset/WbsehnSL4ZeTPJo6r